Wheeled platforms

Abstract

A wheeled platform 100 is disclosed, which is characterized by high mobility and reliability, and which can be used in a wide range of applications including transport and robotic devices. The wheeled platform 100 has fore and aft body portions 130, 132 , each body portion 130, 132 having first and second sides 106, 108 . Overlapping wheels 112, 114, 116, 118 are rotatably attached to the first side 106 and overlapping wheels 120, 122, 124, 126 are rotatably attached to the second side 108 . The fore body portion 130 can be connected to the aft body portion 132 via an articulation element 133.

1. A wheeled structure, comprising:
 a body having at least first and second side portions and having a profile in a center plane, the profile comprising a top-of-body profile; 
 first and second sets of wheel elements rotatably attached to the first and second side portions, respectively; 
 a tail element pivotally coupled to a portion of the body, the tail element being pivotally coupled to the body via an articulation element and substantially conforming to and substantially within the top-of-body profile when in a stowed position; and 
 a drive module coupled to the tail element to control the movement of the tail element between a first, stowed position and a second position where said tail element can make selective contact with a ground plane, wherein the drive module is operable to control, in a continuously variable manner, the angle and position of the tail element relative to the body, so that the tail element can assist in enabling the wheeled structure to traverse steep or difficult terrain; 
 wherein the first and second sets of wheel elements each comprise at least front and rear wheels; and 
 wherein the tail, when in the stowed position, is disposed substantially entirely within a wheeled structure profile defined by a plane substantially tangent to a topmost point of the front and rear wheels and within a perimeter defined by the front and rear wheels. 
 
   
   
     2. The wheeled structure of  claim 1 , wherein the articulation element is a hinge. 
   
   
     3. The wheeled structure of  claim 1 , wherein the articulation element is a pivot. 
   
   
     4. The wheeled structure of  claim 1 , wherein the articulation element is a flexible body portion. 
   
   
     5. The wheeled structure of  claim 1 , wherein there is no overlap between adjacent wheel elements of the first and second sets of wheel elements. 
   
   
     6. The wheeled structure of  claim 5 , wherein the wheel elements of the first and second sets of wheel elements, respectively, are aligned in a row. 
   
   
     7. The wheeled structure of  claim 6 , wherein each of the first and second sets of wheel elements is comprised of at least a first end wheel element, an intermediate wheel element, and a second end wheel element, and wherein the intermediate wheel element is configured to contact the ground plane, and the first and second end wheel elements are configured to selectively contact or be adjacent to the ground plane. 
   
   
     8. The wheeled structure of  claim 1 , wherein when the tail is articulated furthest forward with respect to the body, the tail is long enough to contact a step forward of a forwardmost wheel element of either of the first and second sets of wheel elements. 
   
   
     9. The wheeled structure of  claim 1 , wherein the tail is configured to contact a first step of a stairway and lift a forwardmost wheel element of either of the first or second sets of wheel elements to attain the first step. 
   
   
     10. A wheeled structure, comprising:
 a body having at least first and second side portions; 
 a first end wheel element, an intermediate wheel element, and a second end wheel element rotatably attached to the first and second side portions, respectively, the intermediate wheel element having a wider track than the first end wheel element and the second end wheel element; 
 wherein each first end, intermediate, and second end wheel elements is arrayed with a selected degree of rocker of the wheel elements coupled to the body, wherein the intermediate wheel element is always in contact with the level ground plane, and the first and second end wheel elements are selectively in contact with or adjacent to the level ground plane to enable the wheeled structure to turn-in-place, enhance stability, and to reduce friction losses on smooth terrain, and further wherein the first end, intermediate, and second end wheel elements rotatably attached to the first and second side portions, respectively, are collectively arrayed in a geometrical arrangement having left-right and fore-aft symmetry; 
 wherein the first and second sets of wheel elements each comprise at least front and rear wheels; and 
 wherein the tail, when in the stowed position, is disposed substantially entirely within a wheeled structure profile defined by a plane substantially tangent to a topmost point of the front and rear wheels and within a perimeter defined by the front and rear wheels. 
 
   
   
     11. A wheeled structure, comprising:
 a body having at least first and second side portions; 
 a first end wheel element, an intermediate wheel element, and a second end wheel element rotatably attached to the first and second side portions, respectively; 
 a tail element pivotally coupled to a portion of the body, the tail element being pivotally coupled to a portion of the body via an articulation element; and 
 a drive module coupled to the tail element to control the movement of the tail element from a first, stowed position to at least one second position where said tail element can make selective contact with terrain; 
 wherein at least one wheel element is substantially scalloped in profile, and 
 wherein the substantially scalloped profile is selected such that a concave portion of the scallop profile is operable to substantially engage a bullnosed stair step edge. 
 
   
   
     12. The wheeled structure of  claim 11  wherein the intermediate wheel elements having a wider track than the first end wheel element and the second end wheel element. 
   
   
     13. The wheeled structure of  claim 11  wherein the tail element, when in the at least one second position, can make selective contact with a level ground plane. 
   
   
     14. The wheeled structure of  claim 11  wherein at least one end wheel element is scalloped, and wherein at least one intermediate element is substantially smooth in profile, thereby facilitating turn-in-place.